diff --git a/ext/curses/.cvsignore b/ext/curses/.cvsignore
index f3c7a7c5da..fc802ff1c2 100644
--- a/ext/curses/.cvsignore
+++ b/ext/curses/.cvsignore
@@ -1 +1,2 @@
 Makefile
+mkmf.log
diff --git a/ext/dbm/.cvsignore b/ext/dbm/.cvsignore
index f3c7a7c5da..fc802ff1c2 100644
--- a/ext/dbm/.cvsignore
+++ b/ext/dbm/.cvsignore
@@ -1 +1,2 @@
 Makefile
+mkmf.log
diff --git a/ext/etc/.cvsignore b/ext/etc/.cvsignore
index f3c7a7c5da..fc802ff1c2 100644
--- a/ext/etc/.cvsignore
+++ b/ext/etc/.cvsignore
@@ -1 +1,2 @@
 Makefile
+mkmf.log
diff --git a/ext/fcntl/.cvsignore b/ext/fcntl/.cvsignore
index f3c7a7c5da..fc802ff1c2 100644
--- a/ext/fcntl/.cvsignore
+++ b/ext/fcntl/.cvsignore
@@ -1 +1,2 @@
 Makefile
+mkmf.log
diff --git a/ext/gdbm/.cvsignore b/ext/gdbm/.cvsignore
new file mode 100644
index 0000000000..fc802ff1c2
--- /dev/null
+++ b/ext/gdbm/.cvsignore
@@ -0,0 +1,2 @@
+Makefile
+mkmf.log
diff --git a/ext/nkf/.cvsignore b/ext/nkf/.cvsignore
index f3c7a7c5da..fc802ff1c2 100644
--- a/ext/nkf/.cvsignore
+++ b/ext/nkf/.cvsignore
@@ -1 +1,2 @@
 Makefile
+mkmf.log
diff --git a/ext/pty/.cvsignore b/ext/pty/.cvsignore
index f3c7a7c5da..fc802ff1c2 100644
--- a/ext/pty/.cvsignore
+++ b/ext/pty/.cvsignore
@@ -1 +1,2 @@
 Makefile
+mkmf.log
diff --git a/ext/readline/.cvsignore b/ext/readline/.cvsignore
index f3c7a7c5da..fc802ff1c2 100644
--- a/ext/readline/.cvsignore
+++ b/ext/readline/.cvsignore
@@ -1 +1,2 @@
 Makefile
+mkmf.log
diff --git a/ext/sdbm/.cvsignore b/ext/sdbm/.cvsignore
index f3c7a7c5da..fc802ff1c2 100644
--- a/ext/sdbm/.cvsignore
+++ b/ext/sdbm/.cvsignore
@@ -1 +1,2 @@
 Makefile
+mkmf.log
diff --git a/ext/socket/.cvsignore b/ext/socket/.cvsignore
index f3c7a7c5da..fc802ff1c2 100644
--- a/ext/socket/.cvsignore
+++ b/ext/socket/.cvsignore
@@ -1 +1,2 @@
 Makefile
+mkmf.log
diff --git a/ext/syslog/.cvsignore b/ext/syslog/.cvsignore
index f3c7a7c5da..fc802ff1c2 100644
--- a/ext/syslog/.cvsignore
+++ b/ext/syslog/.cvsignore
@@ -1 +1,2 @@
 Makefile
+mkmf.log
diff --git a/ext/tcltklib/.cvsignore b/ext/tcltklib/.cvsignore
new file mode 100644
index 0000000000..f3c7a7c5da
--- /dev/null
+++ b/ext/tcltklib/.cvsignore
@@ -0,0 +1 @@
+Makefile
diff --git a/ext/tk/.cvsignore b/ext/tk/.cvsignore
index f3c7a7c5da..fc802ff1c2 100644
--- a/ext/tk/.cvsignore
+++ b/ext/tk/.cvsignore
@@ -1 +1,2 @@
 Makefile
+mkmf.log